">
Geometry Calculator

Pythagorean Theorem Calculator

Find the missing side of a right triangle from the other two sides and check whether the hypotenuse is valid.

Instant answer Formula breakdown Browser-based Mobile friendly
Interactive calculator

Enter your values

Use the example values or replace them with your own. Required validation happens before the calculation.

Ready
Calculated answer

Result

Community rating Rate this page Loading community rating…
Simple workflow

How to use the Pythagorean Theorem Calculator

Follow these steps to get a reliable result and understand how it was produced.

1

Enter two side lengths and leave one blank.

2

Square the known sides and rearrange a²+b²=c².

3

Take the positive square root for the missing length.

Understanding the calculation

The hypotenuse c is opposite the right angle and must be the longest side. Leave exactly one side blank.

a²+b²=c²

The result panel substitutes your numbers into this relationship and shows the important intermediate values.

Common uses

  • Construction diagonals
  • Right-triangle homework
  • Distance on coordinate grids

Accuracy tips

  • The theorem applies only to right triangles.
  • The hypotenuse must be the longest side.
  • Side lengths must be positive.
Helpful answers

Pythagorean Theorem Calculator FAQs

Important details about formulas, inputs, limitations, and result interpretation.

Which side is c?

c is the hypotenuse, opposite the 90-degree angle.

Can I solve for a leg?

Yes. Enter the other leg and hypotenuse, leaving the desired leg blank.

Why can the square-root expression become negative?

That happens when the entered hypotenuse is not longer than the known leg.

Does this determine whether any triangle is right-angled?

You can compare whether the largest side squared equals the sum of the other two squares.

Keep exploring

Try another useful tool from the same collection.

Volume & Surface Area Calculator Calculate volume and total surface area for cubes, rectangular prisms, spheres, cylinders, cones, pyramids, hemispheres, and ellipsoids. Circle Calculator Calculate diameter, circumference, area, semicircle area, and arc-related reference values from a radius. Advanced Area Calculator Calculate the area of rectangles, squares, circles, triangles, parallelograms, trapezoids, ellipses, and regular polygons. Coordinate Geometry Calculator Find distance, midpoint, slope, direction angle, and line equation from two Cartesian coordinate points. Triangle Calculator Use three side lengths to validate a triangle and calculate perimeter, semiperimeter, area, angles, and triangle type. Linear Equation Solver Solve a one-variable linear equation in the form ax + b = 0 and verify the solution by substitution. Factorial, Permutation & Combination Calculator Calculate n factorial, ordered arrangements nPr, and unordered selections nCr for whole-number inputs. Profit Margin Calculator Calculate gross profit, profit margin on revenue, markup on cost, and break-even relationship from cost and selling price.
Practical tool guide

Using Pythagorean Theorem Calculator effectively

Find the missing side of a right triangle from the other two sides and check whether the hypotenuse is valid. This page is designed to help you calculate a result with a clear browser-based workflow rather than making you install a separate utility for a small task.

How to use it

Enter the known values, select the right unit or formula option, calculate the result, and confirm that the inputs use consistent units.

Best used for
  • quick study calculations
  • everyday numeric checks
  • comparing values and units
What to verify

Double-check units, decimal precision and the values you enter, especially when the result will be used for finance, engineering or other high-impact decisions. Rounding and user-entered values can affect the result. For professional or safety-critical work, verify calculations independently.

Expected: A numerical result based on the values, formula and units selected in the tool. Avoid: Mixing units, percentage points and percentages, or relying on rounded inputs for a high-impact calculation.

Why this workflow matters

A calculator is only as reliable as the values and units entered into it. Use Pythagorean Theorem Calculator to speed up routine arithmetic or formula work, then do a quick reasonableness check on the magnitude and sign of the answer. When a calculation affects money, measurements, engineering or another high-impact decision, verify the formula and inputs independently rather than relying on a single automated result.

⌂All Tools ◫Device ◩Images ▤PDF ▧Resume ∑Math AaText ↗SEO ◇Misc